RESERVOIR CHARACTERIZATION PROVIDES OPTIMIZED COMPLETION STRATEGY IN THE MONTEREY SHALE OF SOUTH BELRIDGE FIELD

Reservoir characterization in the Miocene Monterey Shale formation is difficult due to a high degree of heterogeneity. Lithology, texture, and silica phase can vary widely, rendering standard saturation analysis of limited use. In addition, natural fractures can help or hinder completion strategies. A robust approach has been adopted to overcome the limitations of standard characterization techniques. This approach uses spectral gamma ray and elemental capture spectroscopy to improve lithologic definition including additional minerals. It uses dielectric measurements to understand changes to the near wellbore region due to invasion, and also to provide an independently derived saturation analysis. It also uses resistivity imaging to characterize the rock texture and to identify faults and fracture systems. Finally, it uses Stoneley wave acoustic response to identify permeable features observed in the images. Combining these methods can provide a more complete characterization that helps define an optimum completion strategy, combining natural and stimulated completions. Selective hydraulic stimulations using coiled tubing methods have shown to be effective in certain zones but quickly add cost to the well, requiring increased production to maintain profitability. Identification of zones capable of producing without hydraulic stimulation greatly increases the profitability of the well.